<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        div {
            position: relative;
            margin: 0 auto;
            width: 960px;
            height: 600px;
        }

        .mask {
            width: 100%;
            height: 100%;
            background: url("img/stainless-steel-fork-near-clear-glass-on-tray-1510690.jpg") no-repeat center center;
            background-size: cover;
            filter: blur(10px);
            transition: .3s;
        }

        p {
            position: absolute;
            top: 0%;
            left: 0;
            width: 100%;
            height: 100%;
            text-align: center;
            z-index: 1;
            font-size: 180px;
            font-weight: bold;
            background: url($img) no-repeat center center;
            background-size: cover;
            text-shaodw: 2px 2px 2px 2px #fff;
            -webkit-background-clip: text;
            color: transparent;
            animation: move 4s ease-in infinite alternate;
        }

        @keyframes move {
            0% {
                line-height: 100px;
                font-size: 100px;
            }
            100% {
                line-height: 600px;
                font-size: 1500px;
            }
        }
    </style>
</head>
<body>
<div>
    <div class="mask"></div>
    <p>Â·</p>
</div>
<div class="a">

</div>
<div class="a"></div>
<div class="a"></div>
<script>
    var a=5;
    var b=document.getElementsByClassName('a');
    if(--a > --b.length){
        console.log(a,--b.length);
    }
    console.log(--b.length)
</script>
</body>
</html>